1. Field of the Invention
The invention relates to an apparatus and a method for determining travel data of a travel device whose wheels or rollers do not always have ground contract, with a path measuring device or odometer on at least one roller, namely a measuring roller.
2. Description of the Prior Art
Numerous travel or movement devices exist, particularly for sport purposes, but also for movement purposes, such as roller skates and in particular inline skates, in which the rollers do no permanently have contact with the ground. If the rollers of such travel devices are to be used for determining travel data, such as in particular the path length covered and from which with an additional time measurement it is possible to derive an average speed, it is far from easy to obtain correct data, because the "apparent" path covered in the case where there is no ground contact through the rotary path of the outer circumference of the rollers used for path measurement purposes is not identical to the path actually covered and instead significant errors occur.
Thus, when skating by means of inline skates, i.e. sport devices equipped with four or more rollers arranged successively in a line and mounted in ball bearings, a distinction is made between two movement types. These are on the one hand by rolling movement and on the other by running movement. When rolling both skates are in contact throughout the rolling phase with the ground. However, when running alternately the right and left skate are in contact with the ground. Thus, when rolling, the precisely covered path length is given by the distance covered by the rollers of the inline skate, whereas when running for each skate there is a partial path length where this does not apply.